Electrical oscillator



Patented Mar. 10, 1925.

:ELECTRICAL-fOSQILLATQR.

f LAND, a Citizen of tho-UiitedStateS, residing at il/Iontclair, -infthe county, of' EsseX and S.ta te.. of`` New, Jersey, 4( post-oglffice :ad-

:dress No.- '55 Liberty`Street ,NeW gYork city),

v` have invented certain new and us`eful' 1inzprovements in Electrical Oseillators, `ofV "which `the following is .Spec'iiicationj 'The `invention herein' v,described relates to an improvement in electric; oscillators, Ap articularly oscillators oi. the regenerative type, in which energy is supplied'from a -Q 'sourceofpower to, an oscillating: circuitin o energy supply iscontrolledfby the oscillations themselves.

synchroni'sm With thefoscillationa and the 'f ln my U. IS. 4"Patents No. 829,4;47, No. l829,934 and No. 97 3,8%,"1 have `'described various forms of oscillators of thistype, in which the supply of energytofthefoscil-- lating circuit is introduced 'througlna sen- .,-sitiveugap or gaps, ,and v1controlled byl a magnetic or electrostatic iel'd producedor :25,

controlled by the oscillations in the oscillating A circuit. In my U. S. VPatent No. 1,340,193, dated May 18, 1920,I have described an yIDProvement in oscillators of this type,uvvhereby purity of Wave forinsis secured, and including the' feature of an oscillating circuit' having inductanee-,and' vea.- pacityireactances which arellarge with respect to the other impedances of the systemwith whichitsis associated. The specie ,means (there. set fo-rthtor securing 'this v result includes a stepdoyvn couplingof the systemjincluding thepovver circuit to the oscillating circuit. AThis latter specific/ficature is peculiarly z rpgplicable inl the ,ca-se Where 'the sensitive gapemployedgis a thermionic tubefhavingjhighimpedance, as is v"fully explained' in that application.

The present invention Vrelates to another application,V of. theprinciple of securing gapprogimately puresinusoidal. A(,Jscllations "by Vvmeans of' a` heavily Iloaded oscillating-k circuit, ilexiblycoupledfto the power system; that, is, ani-oscillating circuitfhaving inductano@ and Capacity reeotonoes which are :large with respect to fthe Ie151?'ective vimpedance of 'the system 'with which it is associated, and in the present caseroupled VA thereto by a step-up y tnansformer Orfby an equi-valent electrostatic jor .other coupling, 'paraoularlyfprlioablolinianiosoillater 'including sensitive' galrhaving relatively 19,20. Serial No., 378,435.

lowfiinped-ance, .such as the mercury y,arc ,oscillators y c lescribed .in Lmy patents Qabove ,cited. It involvespther novel .andnseful Y, In the pdmwiogria 1..` shows .inapplication ,of the ,invention `to a .inercuryarc l oscillator controlled by magnetic incid.

*Fig. `2 show-s `an applicationto ian,7,oscillator .of vthe. negative resistance:tynesoh as [is described in f my U. S. ""Ratent "N,o...-1

"In certain ,forms of electrical .l oscillator the .Wajve Aformof the osc'illationY- is very impure because ,of .the non-gsinusoidalfcharacter of lthepoWer supplyand fthe rigid coupling of vthe Voscillating circuit tothe Sensitive .leap c oro,thor.-roven-transforming medium. By the use of `,the presentiinvention 'I obtain .a .rresulttanalogous to that `secured :by e 'heavy ",.fly Wheel oonno'oted @to @its primer .mover by ,la ,flexible or yielding coupling, the ,large momentum of .the fly Wheel and the Aflexibility, of the, coupling cooperating ,y to absorb irregular 'fluctuations in 'the driving force.

I employa :heavily loaded. oscillating circuit, flexibly coupled; tojthe power system; A that is, anfoscillating circuit .Whose capacity ,and .inductance reactances arelargewvith respectto the `impedance of the coupling ineans `and itsassociated` circuits, relative ,toet-he, oscillating. cireuitwadapting the secl'onfdary of fthe coupling .means ,tothe1 require- VI nents vof 'relatively free A oscillation, and adapting s the primary .to the f. requirements 4fo'f absorbingialid trnsmittiegfenosgyfrom ithe @energy transforming medinm to the .osolflatirgorotlT T-ho ooaplne is ideSigned to secureltan` eiiizientenerg'gfy transfer vvithvtout imposing rigidity on the oscillating circuit.

'The Tpresent invention isnadeptd, partiellladyI to leso in .Comi.ooton :with aeenst-v een :.or `1other Power i f-ranforoo.ine medium ,o'f relatively low ;v impedance. "With, such, a. inedium iit' is desirable 1vto ,ernplcy a stepnup coupling between the power circuit. and the osllatine circuit So 'that the @Conditions 4-.above stated-maybemot wthzan oscillating System having felemeots of ,Convenient proportions. 'The seoondalyrimpedanoo is ,modeasmall ,With-@fellation :to the otheriw "pedances off the oscillating circuit, thesecondery of the.. Ycolliding .meensgthes' '.bne :adapted uto .sustainthefosolletiensaithovt 'forcingfirreg1ates 'upon fthem, .and the primary being adapted to absorb and traiismit energy freely from the power transmitting medium, which is one of small impedance carrying relatively large currents at a low voltage, such as a high vacuum mer cury vapor tube, or a medium of intermediate characteristics, such as various forms of electric arc. The coupling may be elec tro-magnetic, as in the four examples here illustrated, or electrostatic, as in Fig. 2 of my Paten'tNo. l1,340,193 above referred to.

Consideringspecifically the case of an electromagnetic coupling, which I' prefer, the power circuit is associated with the oscillating cii'cuitby a transformer whose secondary, located in the oscillating circuit, has an impedancesufiiciently small with respect to the inductance and capacity reactances of the oscillating circuit to prevent undue dis- .tortioii ofthe wave form, and whose primary is so related to the electrical constants of the sensitive gap or other energy transforming medium as to insure an eflicient transfer of energy. In general, the primary reactance should be comparable to the impedance of the power transforming medium. Usually I prefer to employ a close couplingbetween the primary and the secondary, or specifically one in which the major part of the inductance of the power circuit is interlinked with the secondary. This close coupling, however, does not impose rigidity on the oscillating circuit, since the secondary reactance is small compared to the other reactances of the circuit- The ratio of transformation is a step-up ratio and the condition of securing sinusoidalv oscillations is complied with by making the inductance reactances of the coils L, L and the capacity react-ance of the condenser vC large with respect to the other iinpedances of the oscillating system. Thus the impedance of the secondary .s is made small with respect to these reactances, and the ratio of thisimpedance to the primary impedances of p1 and p2 is designed to suit the impedance of the sensitive gap. It will be understood that, when comparing the impedances of the oscillating system, the primary impedances will be reduced to their vequivalent impedances in the oscillating circuit, as determined by the ratio of transformation of the coupling transformer.

YWhen the power transforming medium is a sensitive gap of low impedance, such as the various forms of mercury or other arcs, described in my patents referred to Nos. 829,447, 829,984, and 973,826, the current drawn from the power supply is usually comparatively large, and the primary flue: tuations or. oscillations of this current prof duced bythe control field are also relatively Iarge.

Iii the preferred form of apparatus shown rectly connected to the sensitive gap or gaps, so that the oscillations in this circuit have the same order of magnitude as the luctua tions of the ypower current. It is not always convenient, however, to use currents in the oscillating circuit of the same order of,

magnitude as the power currents. In the case of my patent 1,340,193 herein referred to, thefluctuations of current in the therinionic bulb are relatively very small,lience a step-down coupling is provided which permits the use of relatively large vcurrents in the oscillating circuit. On the Vother hand, it is sometimes desirable to employ an os; cillating circuit carrying currents much smaller than the current fluctuations of the power circuit. In suoli cases a step-up coupling is desirable. Such a case arises, for example, in a mercury arc oscillator when very low fre uencies are to be generated. To secure suc low frequency without the use of excessively large condensers requires a large inductance in the oscillating circuit.

lVhen the inductance is too large to 4be eff p employed as field coils to perform the niagnetic control or commutation of energy in the sensitive gap.

Fig. 2 shows an application of the invention to an oscillator of the negative resistance type, such as described in my U. S,

Patent No.'1,152,675. vA similar arrangement is eifective in connection with an arc oscillator of the well known type. It is particularly useful in connection with the arc oscillator because of the wide departure of the power current from the sinusoidal form due to the extinction of the arc at each oscillation.

In this arrangement, as in the other, the` power circuit includes a primary coil 29, of

impedance comparable to the impedance of y the arc or generatorl tube, coupled, prefera* bly closely, toa secondary coil s1 in the oscillating circuit, si, L, C L', the secondary impedence being small with respect togthe inductance and capacity reactances..y By virtue of this coupling and proportioning of the system oscillations of approximately pure wave form are secured notwithstanding the irregular character of the power sup- 1. In an electrical oscillator, a power transforming medium, a power circuit asso @iet-e1, therewith? a heavily; leaded vrille@- ing system, and a step-up couplin means between the circuits which is flexile with relation to the oscillating circuit and stiff with relation to the power circuit, substantially as set forth.

2. In an electrical oscillator, a power transforming medium, a power circuit associated therewith and step-up coupling means between the oscillating circuit and the power circuit whose mutual reactance constitutes a small part of the capacity and inductive reactance of the oscillating circuit and a relatively large part of the reactance of the power circuit, substantially as set forth.

3. In an electrical oscillator, a power transforming medium of low impedance, a power circuit associated therewith, an oscillating circuit associated with the power circuit by a transformer having a primary reactance comparable with the impedance of the energy transforming medium and a larger secondary reactance that is small compared to the capacity and inductance reactances of the oscillating circuit, substantially as set forth.

4. In an electrical oscillator, a power transforming medium of low impedance, a power circuit associated therewith, an oscillating circuit associated with the power circuit by a transformer having a primary reactance comparable with the impedance of the energy transforming medium and a larger secondary reactance that is small compared to the capacity and inductance reactances of the oscillating circuit, and a close coupling between the primary and secondary reactances, substantially as set forth.

5. In an electrical oscillator, a power transforming medium, a power circuit associated therewith, and an oscillating circuit associated with the power circuit by a step-up transformer whose primary reacance is comparable to the impedance of the power transforming medium and Whose secondary reactance is small with respect to the reactances of the oscillating circuit, substantially as set forth.

6. In an electrical oscillator, a power transformin medium of low impedance, a power circuit associated therewith, an oscillating circuit associated with the power circuit and step-up coupling means between the power circuit and the oscillating circuit comprising the major part of the reactance of the power circuit and a minor part of the reactance of the oscillating circuit, substantially as set forth.

7 In an electrical oscillator, a power transforming medium of low impedance, a power circuit associated therewith and an oscillating circuit associated with the power circuit by a step-up coupling whose secondary reactance is small compared with the reactances of the oscillating circuit, substantially as set forth.

8. In an electrical oscillator, a power transforming medium of low impedance, a power circuit associated therewith, an os cillating circuit associated with the power circuit by a step-up coupling whose reaction on the oscillating circuit is small compared with the other reactances of the circuit, and means whereby the oscillations of the oscillating circuit control the transfer of energy in the power transforming medium, substantially as set forth.

This specification signed and witnessed this 30th day of April, 1920.V

FREDERICK K. VREELAND.

Witnesses:

FRANK L. DYERs, CATHARINE D. JORDAN. 

